Waterjet propulsion unit for water craft with control elements for changing the direction of thrust of the waterjet

Abstract

Water jet propulsion unit for watercraft having a pump and stators arranged upstream and downstream of the pump for eliminating turbulence in the entering water and in the water jet generated by the pump, having coaxially arranged nozzles which are associated with the respective stator and are supported so as to be displaceable axially independently of one another, and having a switchable gear unit for driving the pump in the clockwise or counterclockwise direction in order to change the direction of motion of the watercraft, the water jet propulsion unit being supported at the watercraft so as to be swivelable by ±90° approximately vertically to the axis of rotation of the pump rotor.

What is claimed is: 
     
       1. A water jet propulsion unit for a watercraft comprising: a housing;   a pump which is arranged within said housing, said pump including a rotor and stators with blades;   first and second displaceable nozzles which are supported by said housing and respectively positioned on an inlet side and an outlet side of said pump, said first and second nozzles being provided to generate and change a propulsive water jet whose effective direction can be reversed by changing a rotating direction of said rotor;   hydraulic means for displacing said first and second nozzles in an axial direction, independent from one another, in such a manner that when one of said first and second nozzles is placed in a maximum open position, the remaining nozzle is placed in a minimum open position; and,   rotating means for rotating said housing at least ±90° around an axis which is perpendicular to an axis of rotation of said pump;   wherein, said first and second nozzles are arranged coaxially in a mirror-inverted manner, and include a conical outer surface with an angle, as measured relative to said housing, which corresponds to a slope of blades on said stators, and   said housing widens in a radial outward direction in a region adjacent to ends of blades on said stators to form an elliptical channel between said nozzles and said housing.   
     
     
       2. The water jet propulsion unit according to claim 1, wherein said rotating means drives the rotor of the pump in a clockwise direction as well as a counterclockwise direction by a distributor gear unit which is constructed as a universal gear and whose gear branches can be activated via a sliding coupling, where a drive shaft of the distributor gear unit forms a swivel axis of the water jet propulsion unit. 
     
     
       3. The water jet propulsion unit according to claim 2, wherein a transmission of power between the distributor gear unit and the rotor is effected by ring gears associated with the stators. 
     
     
       4. The water jet propulsion unit according to claim 1 wherein said water jet propulsion unit is a main propulsion unit for watercraft. 
     
     
       5. The water jet propulsion unit according to claim 1 wherein said water jet propulsion unit is an auxiliary propulsion unit for watercraft. 
     
     
       6. A water jet propulsion unit for a watercraft comprising: a housing;   a pump which is arranged within said housing at an angle (β) measured relative to a center axis of said housing, said pump including a rotor and stators with blades;   a displaceable nozzle which is supported by said housing and positioned on one of an inlet side and an outlet side of said pump, said nozzle being provided to generate and change a propulsive water jet whose effective direction can be reversed by changing a rotating direction of said rotor;   hydraulic means for displacing said nozzle in an axial direction between a maximum open position and a minimum open position; and,   rotating means for rotating said housing at least ±90° around an axis which is perpendicular to said center axis of said housing;   wherein, said displaceable nozzle functions as one of a controllable inlet and outlet, depending on a rotating direction of said rotor of said pump, and includes a conical outer surface with an angle, as measured relative to said center axis of said housing, which corresponds to a slope of blades on said stators, and   said housing widens in a radial outward direction in a region adjacent to ends of blades on said stators to form an elliptical channel between said nozzle and said housing.